Tuesday, September 1, 2009

Many of you know that I love my Kindle. It is like a small lapdog. I am carrying it everywhere and it occasionally draws attention to itself. I have run into some issues where the Kindle has rendered poorly though. It reminds me most of when an ink jet printer is running out of ink or has clogged heads and the text is really faint and grainy. Now, for an ink jet printer, I can understand this. For eInk, I am a little confused.

When the symptoms would happen, I would flip pages backwards and forwards for a while trying to clear out whatever it was that was making the image blurry. It usually cleared up in a few flips of the page and I would go back to reading. Sometimes, I would read it while it was still blurry because it was being particularly resistant to clearing up.

This issue nagged and nagged at me. I don't like to leave problems without finding a reasonable cause for why they happen. In the software world, I have found that if something breaks once, it will break again. Typically, it will break in the same way at multiple locations around the world almost simultaneously. Ignore software problems at your own peril. Since I could not reliably reproduce the problem or make it go away, I figured there was some issue that was affecting its performance. I considered several factors: ambient temperature, duration of use, speed of flipping pages, ... I started to pay far more attention to the problem when it occurred and looked for patterns.

I noticed a few patterns right away. The problem was not consistent throughout the screen. Any part of the screen could be affected. Usually a large portion of the screen or the whole screen was affected at one time. I was frequently on the move (either walking, in my car, waiting in line, ...). While this made me even more suspicious about ambient temperature, I noticed that cold or hot days did not make a difference. One day, I was holding the device in a way that covered part of the screen, flipped the page, and figured out the pattern.

The portion of the screen that I was covering was bright and vibrant and the rest was affected by this issue. I quickly determined that it was UV rays that were affecting the image. My Kindle is sun sensitive. Now, I am sun sensitive and this would explain why the Kindle would only act up when I was on the move. Most of the time, I was either out of the sun or behind UV protected glass. For this blog entry, I took a few moments with my car parked out in the sun and took some candid shots of my Kindle. (I hope it has a nice modeling career ahead of it).

I started out with rendering a page on my Kindle inside my car (UV protection in the glass). You will notice that the Kindle image is very sharp and quite easy to see even in the direct sunlight on a bright California afternoon.

I then, without moving the Kindle, advanced to the next page. The difference is pretty striking:

You can see how blurry the kindle is. How much of the text is completely missing and you cannot read much of the page. After that, I thought about a few ways that I might convince and/or show people that this was indeed the issue. One bad render could easily be caused by a temperature difference. A temperature difference could be caused by say, pulling the Kindle out of a car and putting it on the hood on a nice bright California afternoon. While the Kindle surface is a little bit small for this exercise, I tried a few attempts at making patterns on the screen by shading it with my hand. In order to have sharper lines on the display, I placed my hand directly on the device while I flipped pages. Here are two different patterns with before and after shots. Look near where the edge of my hand was and see how big the difference is between the shaded portion and the non-shaded portion.

As a final experiment, and more detailed pattern, I decided to stack some coins on the corner of the Kindle. My Prius hood is a little too steep for them to sit in the middle, so I stacked them up in the corner of the screen. Unfortunately, 2 pennies would not have been a very good example image, or I would have shown you my $0.02.

You can see the influence of the coins, but the pattern is a little blurry. Some of the coin edges are visible but they are not too crisp.

Kindle's screen reflects light like ordinary paper and uses no backlighting, eliminating the glare associated with other electronic displays. As a result, Kindle can be read as easily in bright sunlight as in your living room.

I have to say, the Kindle does not quite live up to the advertising in this case. It does have glare, it is not bad, but it is there. Also, while you can read amazingly well in bright sunlight, you cannot read after turning the page. I turn lots of pages.

I have tried this on at least two kindles (one original, one Kindle 2) and have seen a consistent issue. I have to say, for a device that is dedicated to reading, not being able to read in the sun is a little disconcerting. I think an inexpensive UV filter over the screen would both protect it and prevent this from being an issue.